Corresponding author: Kutty Ranjeet (
Rodolfo Reyes Jr.
The length–weight relations of ten fish species representing eight genera and four families and that formed the backbone of the subsistence fishery in the Lakshadweep islands were estimated. These fishes which included four species of tuna [
The relation between body weight and length is important for fishery biology, especially in understanding the state of fish stock and assessing the population structure based on the age- and length-structured models (
The Lakshadweep archipelago, which includes a group of 36 islands lies in the southern Arabian Sea and is the only coral reef complex of India. The fishery in the Lakshadweep islands has traditionally been sustainable and for subsistence. In all the ten of its inhabited islands, fishing is the major source of livelihood. Tuna and needlefishes contribute to about 95% of the total commercial fishery in the Lakshadweep islands and have been historically harvested using pole and line, handline, troll line, and drift gillnet. The bait fishes available in the lagoon are used for chumming of the tuna. Although there have been studies in the past to assess the stock of these species individually (
The Lakshadweep Archipelago includes a group of ten inhabited and 17 uninhabited islands, under the jurisdiction of the Government of India, scattered between 08°16′–13°58′N and 071°44′–074°24′E in the southern Arabian Sea. The samples were collected on a monthly basis between June 2015 to May 2017 from fish landing center of ten inhabited Lakshadweep islands: Androth (
Map of Lakshadweep showing the ten inhabited islands from where fish landing data was collected.
Tuna were collected using a diverse type of gears viz., pole and line, hook and line, handline, and drift gillnets (55–80 mm mesh size), while the needlefishes and halfbeaks were harvested using gillnet (22–55 mm mesh size) and bait fishes using encircling nets (4–6 mm mesh size). Specimens without physical damage were carefully transferred to the laboratory in iced condition and identified following
where
log
Normalization of the data was carried out using log-log plot of the length–weight pairs, and the 95% confidence limits (Cl) of
During the presently reported study, 2474 specimens were measured. The length–weight relation parameters including the number of specimens (
Descriptive statistics and estimated parameters of length–weight relation for the major pelagic species from Lakshadweep waters, southern Arabian Sea.
Family | Species |
|
W [g] |
|
95% CI of |
|
95% CI of |
|
|
---|---|---|---|---|---|---|---|---|---|
|
|
309 | 28.0–136.6 | 350–40 600 | 0.03533 | 0.02672–0.04472 | 2.846 | 2.778–2.913 | 0.957 |
|
765 | 23.9–70.6 | 200–6400 | 0.01779 | 0.01501–0.02108 | 3.018 | 2.973–3.063 | 0.957 | |
|
271 | 23.0–64.0 | 300–3300 | 0.03283 | 0.02482–0.04343 | 2.848 | 2.773–2.922 | 0.954 | |
|
224 | 26.0–61.1 | 380–3200 | 0.02936 | 0.01992–0.04328 | 2.871 | 2.767–2.975 | 0.929 | |
|
|
288 | 45.0–82.3 | 180–1176 | 0.00492 | 0.00284–0.00854 | 2.745 | 2.614–2.877 | 0.854 |
|
103 | 42.0–111.0 | 148–2389 | 0.00208 | 0.00093–0.00465 | 2.963 | 2.778–3.149 | 0.908 | |
|
77 | 40.0–112.0 | 85–1310 | 0.00132 | 0.00067–0.00256 | 2.972 | 2.818–3.126 | 0.951 | |
|
|
70 | 16.0–34.0 | 22–176 | 0.00636 | 0.00455–0.00888 | 2.903 | 2.798–3.007 | 0.978 |
|
|
106 | 1.6–5.3 | 0.013–1.102 | 0.00377 | 0.00338–0.00421 | 3.404 | 3.307–3.501 | 0.979 |
|
261 | 3.0–7.8 | 0.137–2.953 | 0.00455 | 0.00399–0.00517 | 3.130 | 3.055–3.205 | 0.963 |
The
The presently reported study is a comprehensive analysis encompassing landings from all the inhabited islands of Lakshadweep. The results of the presently reported study are also the first estimates for
The authors are thankful to Dr. Tariq Thomas IAS, Director, Department of Science and Technology, Lakshadweep for the valuable suggestions and help provided. The authors appreciate with gratitude the support and facilities provided by Principal, MES Ponnani College, Ponnani. Authors are also thankful to the Department of Science and Technology, Union Territory of Lakshadweep for their logistic and field support. The financial support provided by the University Grants Commission (UGC), New Delhi through the Maulana Azad National Fellowship scheme is deeply acknowledged. Two anonymous reviewers provided useful comments that greatly improved the manuscript.